HHS Designation of Additional Members of the 

Special Exposure Cohort 

under the 

Energy Employees Occupational Illness Compensation Program Act of 2000 

Designating a Class of Employees from 

Santa Susana Field Laboratory – Area IV 

Santa Susana, California

 

HHS Special Exposure Cohort Designation: 

Santa Susana Field Laboratory – Area IV 

Santa Susana, California 
HHS Special Exposure Cohort Designation: 

Santa Susana Field Laboratory – Area IV 

Santa Susana, California 

Page 2

I. Designation 

I, Kathleen Sebelius, Secretary of Health and Human Services, designate the class 

of employees defined in Section II of this report for addition to the Special Exposure 

Cohort (SEC), as authorized under the Energy Employees Occupational Illness 

Compensation Program Act of 2000 (EEOICPA), 42 U.S.C. § 7384q. 

 ____June 18, 2009___ __[Signature on File]__________ 

 Date Kathleen Sebelius 

II. Employee Class Definition 

All employees of the Department of Energy (DOE), its predecessor agencies, and 

DOE contractors and subcontractors who worked in any area of Area IV of the Santa 

Susana Field Laboratory for a number of work days aggregating at least 250 work 

days from January 1, 1955 through December 31, 1958, or in combination with work 

days within the parameters established for one or more other classes of employees 

in the SEC. 

III. Designation Criteria and Recommendations 

Pursuant to 42 U.S.C. § 7384q, for the class defined in Section II of this report, the 

Secretary has determined, and the Advisory Board on Radiation and Worker Health 

(Board) has recommended, that 

(1) it is not feasible to estimate with sufficient accuracy the radiation dose that the 

class received; and 

(2) there is a reasonable likelihood that such radiation dose may have 

endangered the health of members of the class. 

The SEC final rule states in 42 C.F.R. § 83.13(c)(1) that it is feasible in two situations 

to estimate the radiation dose that the class received with sufficient accuracy. First, 

the rule states that radiation doses may be estimated with sufficient accuracy if 

NIOSH has established that it has access to sufficient information to estimate the 

maximum radiation dose for every type of cancer for which radiation doses are 

reconstructed that could have been incurred under plausible circumstances by any 

member of the class. Alternatively, radiation doses may be estimated with sufficient 

accuracy if NIOSH has established that it has access to sufficient information to 

estimate the radiation doses of members of the class more precisely than a 

maximum dose estimate. 

The Board, pursuant to 42 U.S.C. § 7384q, advised the Secretary to designate the 

class as an addition to the SEC in a letter received by the Secretary on May 20, 

2009. 
HHS Special Exposure Cohort Designation: 

Santa Susana Field Laboratory – Area IV 

Santa Susana, California 

Page 3

IV. Designation Findings 

Feasibility of Estimating Radiation Doses with Sufficient Accuracy

The Secretary established the feasibility determination for the class of employees 

covered by this report based upon the findings summarized below. 

 Principal sources of internal radiation exposures for members of the proposed 

class included exposures to a wide array of radionuclides, which could have 

occurred during the performance of reactor or accelerator operations, or the 

performance of research and development activities at the site. 

 NIOSH has documented that it cannot complete the dose reconstructions related 

to this petition with sufficient accuracy. The basis of this finding demonstrates 

that NIOSH does not have access to sufficient information either to estimate the 

maximum radiation dose incurred by any member of the class or to estimate 

such radiation doses more precisely than a maximum dose estimate. 

 NIOSH has concluded that it cannot reconstruct pre-1959 internal doses for the 

evaluated worker class at Area IV of SSFL. NIOSH does not have access to 

sufficient personnel monitoring, workplace monitoring, or source term data to 

bound potential internal exposures from the various radionuclides for the 

evaluated worker class at Area IV of SSFL during the period from January 1, 

1955 through December 31, 1958. Consequently, NIOSH finds that it is not 

feasible to estimate, with sufficient accuracy, the total internal dose for the class 

of employees covered by this evaluation. 

 NIOSH has access to sufficient personnel monitoring and workplace monitoring 

data to bound potential external exposures for workers at Area IV of SSFL during 

the period from January 1, 1955 through December 31, 1958. NIOSH also finds 

it is feasible to reconstruct occupational medical dose with sufficient accuracy for 

workers at Area IV of SSFL. 

 Pursuant to 42 C.F.R. § 83.13(c)(1), NIOSH determined that there is insufficient 

information to either: (1) estimate the maximum radiation dose, for every type of 

cancer for which radiation doses are reconstructed, that could have been 

incurred under plausible circumstances by any member of the class; or (2) 

estimate the radiation doses of members of the class more precisely than a 

maximum dose estimate. 

 The Board concurred with the NIOSH evaluation and recommended the proposed 

class for addition to the SEC. 

 Although NIOSH found that it is not possible to completely reconstruct radiation 

doses for these employees, NIOSH intends to use any available internal and 

external monitoring data that may be available for an individual claim (and can be 

interpreted using existing NIOSH dose reconstruction processes or procedures). 

Further, NIOSH has determined that occupational medical dose for all workers 

can be reconstructed. Therefore, partial dose reconstructions for individuals with 
HHS Special Exposure Cohort Designation: 

Santa Susana Field Laboratory – Area IV 

Santa Susana, California 

Page 4

non-presumptive cancers or fewer than 250 work days’ employment in the class 

period may be performed using these data as appropriate. 

 

Health Endangerment

The Secretary established the health endangerment determination for the class of 

employees covered by this report based upon the findings summarized below. 

(1) Pursuant to 42 C.F.R. § 83.13(c)(3), NIOSH established that there is a 

reasonable likelihood that such radiation doses may have endangered the 

health of members of the class. Pursuant to 42 C.F.R. § 83.13(c)(3)(ii), 

NIOSH specified a minimum duration of employment to satisfy this health 

endangerment criterion as “having been employed for a number of work days 

aggregating at least 250 work days within the parameters established for this 

class or in combination with work days within the parameters (excluding 

aggregate work day requirements) established for one or more other classes 

of employees in the Cohort.” 

(2) NIOSH did not identify any evidence from the petitioners or from other 

resources that would establish that the class was exposed to radiation during 

a discrete incident likely to have involved exceptionally high-level exposures, 

such as a nuclear criticality incident, as defined under 42 C.F.R. § 

83.13(c)(3)(i). 

(3) The Board concurred with NIOSH’s finding that the health of the class may 

have been endangered and defined the class according to the 250-work day 

requirement specified under 42 C.F.R. § 83.13(c)(3)(ii). 
HHS Special Exposure Cohort Designation: 

Santa Susana Field Laboratory – Area IV 

Santa Susana, California 

Page 5

V. Effect and Effective Date of Designation 

The Secretary submits this report on the designation of one additional class to the 

SEC for review by Congress, pursuant to 42 U.S.C. §§ 7384l(14)(C)(ii) and 

7384q(c)(2)(A), as amended by the Ronald W. Reagan National Defense 

Authorization Act for Fiscal Year 2005, Pub. L. No. 108-375 (codified as amended in 

scattered sections of 42 U.S.C.). Pursuant to 42 U.S.C. § 7384l(14)(C)(ii), as 

amended by the Ronald W. Reagan National Defense Authorization Act for Fiscal 

Year 2005, Pub. L. No. 108-375 (codified as amended in scattered sections of 42 

U.S.C.), the designation in this report will become effective 30 days after the date of 

this report’s submission to Congress “unless Congress otherwise provides.” 

VI. Administrative Review of Designation 

The health endangerment determination of the designation provided in this report 

may be subject to an administrative review within HHS, pursuant to 42 C.F.R. § 

83.18(a). On the basis of such a review, if the Secretary decides to expand the class 

of employees covered by this designation, the Secretary would transmit a 

supplementary report to Congress providing the expanded employee class definition 

and the criteria and findings on which the decision was based.